Non-coaxially mounted electric actuator and transmission

ABSTRACT

an electric actuator comprising an electric motor comprised of a motor housing that houses a drive shaft having a drive gear and a drive axis, a transmission comprised of a transmission gear having a gear axis, the drive gear, the transmission gear and the valve pin being drivably interconnected and arranged such that the drive axis and the gear axis are non-coaxially mounted or disposed relative to each other and the valve pin is drivable linearly along the pin axis, wherein one or the other of the motor housing or the transmission housing are removably attached to a top clamping or mounting plate that is mounted upstream of the manifold and fixedly interconnected to a mold.

RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityto U.S. application Ser. No. 15/286,917 filed Oct. 6, 2016 which is acontinuation of U.S. application Ser. No. 14/325,443 filed Jul. 8, 2014the disclosures of which are incorporated by reference in their entiretyas if fully set forth herein.

This application is a continuation-in-part of and claims the benefit ofpriority to U.S. application Ser. No. 14/567,308 filed Dec. 11, 2014which is a continuation of Ser. No. 13/484,336 filed May 31, 2012 whichis a continuation of PCT/US2011/062099 filed Nov. 23, 2011, thedisclosures of both of the foregoing are incorporated by reference intheir entirety as if fully set forth herein.

This application is also a continuation-in-part of and claims thebenefit of priority to U.S. application Ser. No. 14/567,369 filed Dec.11, 2014 which is a continuation of U.S. application Ser. No. 13/484,408filed May 31, 2012 which is a continuation of PCT/US2011/062096 filedNov. 23, 2011, the disclosures of both of the foregoing are incorporatedby reference in their entirety as if fully set forth herein.

This application is also a continuation-in-part of and claims thebenefit of priority to U.S. application Ser. No. 14/311,785 filed Jun.23, 2014.

The disclosures of all of the following are incorporated by reference intheir entirety as if fully set forth herein: U.S. Pat. Nos. 5,894,025,6,062,840, 6,294,122, 6,309,208, 6,287,107, 6,343,921, 6,343,922,6,254,377, 6,261,075, 6,361,300 (7006), 6,419,870, 6,464,909 (7031),6,599,116, 7,234,929 (7075US1), 7,419,625 (7075US2), 7,569,169(7075US3), U.S. patent application Ser. No. 10/214,118, filed Aug. 8,2002 (7006), 7,029,268 (7077US1), 7,270,537 (7077US2), 7,597,828(7077US3), U.S. patent application Ser. No. 09/699,856 filed Oct. 30,2000 (7056), U.S. patent application Ser. No. 10/269,927 filed Oct. 11,2002 (7031), U.S. application Ser. No. 09/503,832 filed Feb. 15, 2000(7053), U.S. application Ser. No. 09/656,846 filed Sep. 7, 2000 (7060),U.S. application Ser. No. 10/006,504 filed Dec. 3, 2001, (7068) and U.S.application Ser. No. 10/101,278 filed Mar. 19, 2002 (7070) andPCT/US2011/062099 filed Nov. 23, 2011 and PCT/US2011/062096 filed Nov.23, 2011.

BACKGROUND OF THE INVENTION

Injection molding systems powered electric actuators have been developedhaving a drive rotor with an axis aligned with the axis of a valve pinto cause the pin to move either upstream or downstream over the courseof the injection portion of an injection cycle in order to raise orlower the rate of flow of fluid material to correspond to apredetermined profile of fluid flow rates for the injection cycle.

SUMMARY OF THE INVENTION

In accordance with the invention there is provided, an apparatus forcontrolling the rate of flow of fluid mold material from an injectionmolding machine to a mold cavity, the apparatus comprising:

a manifold that receives an injection fluid mold material, the manifoldhaving a delivery channel that delivers the injection fluid moldmaterial under an injection pressure to a gate of a mold cavity disposedwithin a mold, the gate being controllably opened and closed by a valvepin having a pin axis, the valve pin being slidably mounted forreciprocal upstream and downstream linear movement along the pin axissuch that a downstream end of the valve pin is drivable into and out ofopen and closed positions relative to the gate,

an electric actuator comprising an electric motor comprised of a motorhousing that houses a drive shaft having a drive gear and a drive axisthat is rotatably mounted within the motor housing and is drivablyrotatable around the drive axis by a source of electrical power orenergy and a transmission comprised of a gear shaft rotatably mountedwithin a transmission housing, the gear shaft having a gear axis and atransmission gear drivably rotatable around the gear axis,

the drive gear and the transmission gear being drivably interconnectedand arranged such that the drive axis and the gear axis arenon-coaxially mounted or disposed relative to each other and such thatdriven rotation of the drive gear around the drive axis rotatably drivesthe gear shaft around the gear axis,

a linear travel converter comprising a travel shaft having a travelaxis, the gear shaft being interconnected to an upstream end of theliner travel converter and the valve pin being interconnected to adownstream end of the linear travel converter,

the interconnection between the converter and the gear shaft beingadapted to convert rotation of the gear shaft to linear travel of thetravel shaft along the travel axis,

the linear travel converter being mounted for controllable upstream anddownstream linear travel together with the valve pin via theinterconnection of the downstream end of the linear travel converter tothe valve pin,

wherein one or the other of the motor housing or the transmissionhousing are removably attached to a top clamping or mounting plate thatis mounted upstream of the manifold and fixedly interconnected to themold.

The valve pin typically comprises a pin stem and a pin connector, thelinear travel converter having a coupling that is reversibly couplableto and decouplable from the pin connector in a radial direction relativeto the travel axis,

the pin stem extending from the linear travel converter into themanifold when the actuator is coupled to the top clamping or mountingplate and the pin connector is received within the actuator coupling,

the actuator being mounted on, to or within the top clamping or mountingplate for radial movement upon decoupling of the actuator from the topclamping or mounting plate such that the pin connector is decouplablefrom the actuator coupling upon said radial movement while the actuatoris disposed on or within the mounting plate, the actuator beingremovable from on or within the mounting plate leaving the valve stembehind extending into the manifold.

The pin connector typically comprises an adapter coupled to a top orupstream end of the stem, the adapter configured to be reversiblyreceivable within the coupling in a radial direction.

The adapter can comprise an enlarged head which is reversibly couplableto and decouplable from the coupling.

The apparatus is preferably adapted to allow the pin connector to travela selected radial distance within the coupling and to remain coupledwhile the top clamping or mounting plate remains coupled to the mold andthe pin stem remains extended into the manifold.

The pin stem is typically mounted to the manifold for radial movement ofthe pin stem together with the manifold relative to the top clamping ormounting plate.

The apparatus is preferably adapted to allow the adapter to travel aselected radial distance within the coupling relative to the axial pathof travel while the mounting plate remains coupled to the mold, the pinconnector remains coupled to the actuator coupling and the pin stemremains extended into the manifold.

The top clamping or mounting plate is typically decouplable from themold leaving the pin stem extended into the manifold when the adapter isdecoupled from the coupling.

The motor housing is preferably removably attached to the top clampingor mounting plate and the transmission housing is removably attached tothe motor housing.

The transmission housing can be removably attached to the top clampingor mounting plate and the motor housing can be removably attached to thetransmission housing.

The actuator is typically interconnected to a controller that includesinstructions that instruct the actuator to drive the valve pin upstreamcontinuously from the second position to the third maximum upstreamposition at one or more high rates of travel that are equal to orgreater than the one or more intermediate rates of travel.

The apparatus can further comprise a position sensor that senses aposition of either the actuator or the valve pin,

the position sensor sensing the position of the actuator or the valvepin and sending a signal indicative of the position of the actuator orthe valve pin to the controller;

the controller instructing the actuator to drive the valve pincontinuously upstream from a first gate closed position to a secondupstream position at a velocity that is less than a maximum velocity atwhich the actuator is capable of driving the valve pin.

The drive gear and the transmission gear can be rotatably interconnectedvia gears or via belt and pulley

In another aspect of the invention there is provided a method of drivinga valve pin in apparatus for controlling the rate of flow of fluid moldmaterial from an injection molding machine to a mold cavity, theapparatus comprising a manifold that receives an injection fluid moldmaterial, the manifold having a delivery channel that delivers theinjection fluid mold material under an injection pressure to a gate of amold cavity disposed within a mold, the gate being controllably openedand closed by a valve pin having a pin axis, a pin connector and a stem,the valve pin being slidably mounted for reciprocal upstream anddownstream linear movement along the pin axis such that a downstream endof the valve pin is drivable into and out of open and closed positionsrelative to the gate, an electric actuator comprising an electric motorcomprised of a motor housing that houses a drive shaft having a drivegear and a drive axis that is rotatably mounted within the motor housingand is drivably rotatable around the drive axis by a source ofelectrical power or energy and a transmission comprised of a gear shaftrotatably mounted within a transmission housing, the gear shaft having agear axis and a transmission gear drivably rotatable around the gearaxis,

the method comprising:

meshing and arranging the drive gear and the transmission gear such thatthe drive axis and the gear axis are disposed at a non-coaxial anglerelative to each other and such that driven rotation of the drive gearrotatably drives the gear shaft around the gear axis,

interconnecting a linear travel converter comprising a travel shafthaving a travel axis to an upstream end of the liner travel converterand interconnecting the valve pin to a downstream end of the lineartravel converter,

adapting the interconnection between the converter and the gear shaft toconvert rotation of the gear shaft to linear travel of the travel shaftalong the travel axis,

mounting the linear travel converter for controllable upstream anddownstream linear travel together with the valve pin via theinterconnection of the downstream end of the linear travel converter tothe valve pin,

removably attaching one or the other of the motor housing or thetransmission housing to a top clamping or mounting plate that is mountedupstream of the manifold and fixedly interconnected to the mold.

The drive gear and the transmission gear are preferably rotatablyinterconnected via gears or via belt and pulley.

Preferably, the actuator is interconnected to a controller that includesinstructions that instruct the actuator to drive the valve pin upstreamcontinuously beginning from the closed position to one or moreintermediate upstream positions at one or more intermediate rates oftravel that are less than a maximum velocity at which the actuator iscapable of driving the valve pin for either a predetermined amount oftime or for a predetermined length of upstream travel.

Most preferably the controller includes instructions that instruct theactuator to drive the valve pin continuously upstream from the one ormore intermediate upstream positions to a maximum upstream position atone or more high rates of travel that are equal to or greater than theone or more intermediate rates of travel.

The apparatus can further comprise a position sensor that senses aposition of either the actuator or the valve pin, the position sensorsensing the position of the actuator or the valve pin and sending asignal indicative of the position of the actuator or the valve pin tothe controller; the controller instructing the actuator to drive thevalve pin continuously upstream from the one or more intermediateupstream positions at the one or more high rates of travel on detectionby the position sensor of the valve pin at the one or more intermediateupstream positions.

The controller can include instructions that instruct the actuator todrive the valve pin at one or more high rates of downstream travel thatare equal to or less than a maximum rate of downstream travel at whichthe actuator is capable of driving the valve pin when the valve pin isdisposed at a maximum upstream position during the course of aninjection cycle.

In such an embodiment, the controller typically includes instructionsthat instruct the actuator to drive the valve pin at one or moreintermediate rates of downstream travel that are less than the one ormore high rates of downstream travel on expiration of a predeterminedamount of time or for a predetermined amount of downstream travel of thevalve pin from the maximum upstream position.

In another aspect of the invention there is provided a method of drivinga valve pin in apparatus for controlling the rate of flow of fluid moldmaterial from an injection molding machine to a mold cavity, theapparatus comprising:

a manifold that receives an injection fluid mold material, the manifoldhaving a delivery channel that delivers the injection fluid moldmaterial under an injection pressure to a gate of a mold cavity disposedwithin a mold, the gate being controllably opened and closed by a valvepin having a pin axis, a pin stem and a pin connector, the valve pinbeing slidably mounted for reciprocal upstream and downstream linearmovement along the pin axis such that a downstream end of the valve pinis drivable into and out of open and closed positions relative to thegate,

an electric actuator comprising an electric motor comprised of a motorhousing that houses a drive shaft having a drive gear and a drive axisthat is rotatably mounted within the motor housing and is drivablyrotatable around the drive axis by a source of electrical power orenergy and a transmission comprised of a gear shaft rotatably mountedwithin a transmission housing, the gear shaft having a gear axis and atransmission gear drivably rotatable around the gear axis,

the drive gear and the transmission gear being drivably interconnectedand arranged such that the drive axis and the gear axis arenon-coaxially mounted or disposed relative to each other and such thatdriven rotation of the drive gear around the drive axis rotatably drivesthe gear shaft around the gear axis,

a linear travel converter comprising a travel shaft having a travelaxis, the gear shaft being interconnected to an upstream end of thelinear travel converter and the valve pin being interconnected to adownstream end of the linear travel converter, the linear travelconverter having a pin coupling that is reversibly couplable to anddecouplable from the pin connector in a radial direction relative to thetravel axis,

the interconnection between the converter and the gear shaft beingadapted to convert rotation of the gear shaft to linear travel of thetravel shaft along the travel axis,

the linear travel converter being mounted for controllable upstream anddownstream linear travel together with the valve pin via theinterconnection of the downstream end of the linear travel converter tothe valve pin,

wherein one or the other of the motor housing or the transmissionhousing are removably attached to a top clamping or mounting plate thatis mounted upstream of the manifold and fixedly interconnected to themold,

the method comprising:

decoupling the actuator from the top clamping or mounting plate,

radially moving the actuator while the actuator is disposed on or withinthe top clamping or mounting plate a distance sufficient to decouple thepin connector from the pin coupling.

Such a method can further comprise removing the actuator from on orwithin the top clamping or mounting plate leaving the valve stem behindextending into the manifold.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings in which:

FIG. 1 is a schematic cross-section of an embodiment of the inventionshowing an actuator comprised of an electric motor and gear box wherethe housing of the motor is fixedly and removably attached to theupstream top clamping plate of the system.

FIG. 2 is a schematic cross-section of another embodiment of theinvention where the housing of the gear box is fixedly and removablyattached to the upstream top clamping or mounting plate of the system.

FIG. 3 is a cross-sectional view of an assembled injection moldingsystem comprised of an electric actuator having a non-coaxial geartransmission according to the invention.

FIG. 3A is a perspective view of the FIG. 3 system.

FIG. 3B is a perspective, partially cut-away view of the motor, motorhousing and components that mount the housing and the valve pin of theFIG. 3 system.

FIG. 4 is a cross-sectional view of an assembled injection moldingsystem comprised of another embodiment of an electric actuator having anon-coaxial gear transmission according to the invention.

FIG. 5 is a perspective view of the FIG. 4 system.

FIG. 6 is a front cross-sectional view of an assembled injection moldingsystem comprised of another embodiment of an electric actuator having anon-coaxial gear transmission according to the invention.

FIG. 7 is a side view of the FIG. 6 system.

FIG. 8 is a perspective view of an assembled injection molding systemcomprised of another embodiment of an electric actuator having anon-coaxial gear transmission with the motor shaft and transmissionassembly shaft connected via pulleys and a belt according to theinvention.

FIG. 9 is a perspective view an electric actuator similar to the FIG. 8actuator where the transmission shaft has a downstream travelling axialshaft that is interconnected to an upstream rotatable shaft, theupstream travelling shaft being adapted to be non-rotatable.

FIG. 10A is an exploded partial schematic view of the pin couplingcomponents of the apparatus shown in FIGS. 1-9, in an assembled state.

FIG. 10B is an exploded partial schematic view showing the pin couplingcomponents of the apparatus shown in FIGS. 1-9, in a disassembled state;

FIG. 10C is an enlarged schematic view of a valve pin head and a pinhead adapter, in an assembled state, according to one embodiment.

FIG. 10D is an exploded view of the pin head and adapter of FIG. 10C ina disassembled state.

FIG. 10E is a perspective view of one embodiment of an electric actuatorcoupled to a valve pin.

FIG. 10F is a schematic partial cross-sectional view of the actuator andvalve pin of FIG. 10E mounted in an injection molding apparatus.

FIG. 10G is a top plan view of the apparatus of FIG. 10E, with theactuator removed.

FIGS. 10H-10M illustrate a series of method steps by which an actuatorcan be decoupled from a valve pin wherein FIG. 10H is a side schematicsectional view (similar to FIG. 10E) showing the actuator and valve pinassembly coupled and mounted in an injection molding apparatus.

FIG. 10I shows the housing of the actuator decoupled from the mountingor clamp plate.

FIG. 10J is a view similar to FIG. 10H after the actuator has beendecoupled from the mounting plate and moved radially to the left todecouple the pin connector or adapter from the coupling at thedownstream end of the actuator; FIG. 10J is a view similar to FIG. 10Ibut showing the actuator to being removed from the mounting plate whilethe valve pin assembly remains behind extended into the manifold.

FIG. 10K is a view similar to FIG. 10J showing the actuator having beenmoved upstream to a position approaching being removed from within therecess provided in the top clamping or mounting plates in which theactuator is disposed when coupled to the plates.

FIG. 10L is view showing the actuator having been completely removedfrom its former position disposed within or on the mounting plateleaving the pin stem behind mounted to the manifold.

FIG. 10M is a view showing the top mounting or clamp plates having beenremoved or decoupled from the mold together with the actuator havingbeen decoupled from the pin connector leaving the pin stem behindmounted to the manifold.

FIGS. 11A-11B show tapered end valve pin positions at various times andpositions between a starting closed position as in FIG. 11A and variousupstream opened positions, RP representing a selectable path length overwhich the velocity of withdrawal of the pin upstream from the gateclosed position to an open position is reduced (via a controllable flowrestrictor) relative to the velocity of upstream movement that the valvepin would normally have over the uncontrolled velocity path FOV when thehydraulic pressure is normally at full pressure and pin velocity is atits maximum;

FIGS. 12A-12B show a system having a valve pin that has a cylindricallyconfigured tip end, the tips ends of the pins being positioned atvarious times and positions between a starting closed position as inFIG. 12A and various upstream opened positions, RP wherein RP representsa path of selectable length over which the velocity of withdrawal of thepin upstream from the gate closed position to an open position isreduced (via a controllable flow restrictor or electric actuator)relative to the velocity of upstream movement that the valve pin wouldnormally have over the uncontrolled velocity path FOV when the hydraulicpressure of a hydraulic actuator is normally at full pressure and pinvelocity is at its maximum;

FIGS. 13A-13D are a series of plots of pin velocity versus position eachplot representing a different example of the opening of a gate lateralto a central gate via continuous upstream withdrawal of a valve pin atone rate or set of rates over an initial flow path RP and at anotherhigher rate or set of rates of upstream withdrawal of the valve pinbeginning at a pin position of FOP and beyond when the fluid materialflow is typically at a maximum unrestricted rate of flow through theopen gate without any restriction or obstruction from the tip end of thepin.

DETAILED DESCRIPTION

FIGS. 1, 2 shows one embodiment of the invention comprised of anelectric actuator 66 assembly that is comprised of an electric motor 64drivably interconnected to a gear 72/190 in a non-coaxially aligned X-Yarrangement. The shaft 60 of the electrically driven motor 64 has anaxis Y, the shaft 60 being rotatably driven by electrical power, theshaft 60 being interconnected to a valve pin 31 through a bevel gearengagement between the head 190 of a screw 72 and the head 191 of anextension member 61 of the motor shaft 60. As can be readily imagined,the screw component 72 can alternatively have threads along its length(in place of the beveled head 190) which mesh with a worm at the end ofextension 61 (in place of the beveled member 191). As shown, the axis Yof the shaft 60 is non-coaxially perpendicular to the axis X of the pin50” to—perpendicular to the axis X of the pin 31 and the actuating screwmechanism 72 such that axial forces which may occur along axis X are nottransmitted along axis Y to the shaft 60.

In the FIGS. 1, 2 embodiment, the screw 197 has a nut 195 integrallyforming the end of the screw 197 which is drivably interconnected to,i.e. screwably engaged with, the actuating screw 72. The pin 31 isslidably mounted in a complementary aperture within manifold 24 formovement along its axis X within melt flow channel 20. The actuatingscrew 72 is mounted via disc 180 to housing 58 which is, in turn,fixedly mounted to mounting plate 45 such that screw 72 is drivablyrotatable around axis X and axially stationary along axis X. Screw 72 isdrivably rotatable around axis X via the screwable engagement betweenbevel gears 190, 191. Shaft extension member 61 is coaxially connectedto the motor shaft 60 (via rigid connection between connecting disc 210and a complementary connecting member attached to shaft 60 which is notshown) such that as the shaft 60 is rotatably driven around axis Y theextension member 61 and its associated bevel gear 191 are simultaneouslyrotatably driven around axis Y. As can be readily imagined, as screw 72is rotatably driven around axis X via the meshed bevel gears 190, 191,pin 31 is translationally driven along axis X via the screwableengagement between nut end 195 and screw 72. Thus the screw 72 acts asan actuating member to and through which axial forces are transmitted toand from pin 31.

FIGS. 1, 3A, 3B, 4, 5 show an embodiment where the electric motor 64component of the actuator 66 is coupled to the top clamp plate 39 viabolts 79 interconnecting motor housing portion 64 a and plate 39.Complementary tapped holes are provided in the upper surface of theupper mounting plate 39 for receiving the bolts 79 and securing themotor housing 64 to the plate 39. This prevents rotational and othermovement of the housing 64 and gear box housing 58 with respect to themounting plates 39, 45 and manifold 24 and the injection moldingapparatus generally. Extending downwardly from the screw 195 is acylindrical projection 74 from which the downstream neck 75 of thecoupler screw extends. Coupled to the downstream end of the neck 75 isthe actuator coupling 80 and extending axially downstream from thecoupling 80 is the valve pin 31. FIGS. 3, 4 show an alternative mountingof the motor housing 64 to the top clamp plate 39 via an extension 64 aand bolt 79, as alternative to the mounting of the transmission gearhousing 58 to the top clamping or mounting plate 45 via bolts 77.

FIGS. 2, 6, 7, 8, 9 show an alternative embodiment where the gear box 58includes four bores 76, one in each corner of the housing, for receivingbolts 77 that removably couple the gear box housing 58 to the lowermounting plate 45. Four complementary tapped holes 50 are provided inthe upper surface 48 of the lower mounting plate 45 for receiving thebolts 77 and securing the gear box housing 58 to the plate 45. Thisprevents rotational and other movement of the housing 58 and itsattached motor 64 with respect to the mounting plates 39, 45 andmanifold 24 and the injection molding apparatus generally. Extendingdownwardly from the screw 195 is a cylindrical projection 74 from whichthe neck 75 of the coupler screw extends. Coupled to the downstream endof the neck 75 is the actuator coupling 80 and extending axiallydownstream from the coupling 80 is the valve pin stem 31. FIGS. 2-10 allshow one alternative arrangement where the gear housing 58 is bolted 77to the top clamp or mounting plate 45 as an alternative to mounting ofthe motor housing 64 to the top clamp or mounting plate 39.

As can be readily imagined the housings 58 and 64 are fixedly connectedto each other by conventional attachment mechanism 502 such that whenone of the housings 58 or 64 is fixedly bolted 77 or 79 to a clamp ormounting plate 39, 45, the other of the two housings 58 or 64 is fixedlymounted to the same plate via fixed connection between 502 the twohousings 58, 64.

FIGS. 1, 2 show the actuator 66 comprised of a transmission assembly 58a that is comprised of a gear box 58 assembled together with the othercomponents of the system to form a stack that includes a nozzle 18mounted in a receiving well 15 formed within a mold plate 13 in aninjection molding stack arrangement. As shown a heated manifold 24 isdisposed between the pair of upstream top clamping or mounting plates39/45 and the downstream mold plates 13/14. The valve pin 31 is mountedto the manifold within a bushing 28 having a complementary internal borefor slidably receiving the pin 31 such that the pin can reciprocallytravel XX along axis X. The valve pin 31 has a downstream distal tip endthat opens and closes a gate aperture 20 that leads to the mold cavity19. In use, the mounting plates 39, 45 and mold plates 13, 14 arefixedly secured together under high clamp pressure, so as to withstandhigh injection molding forces. A nozzle 18 extends through a bore 15 inthe lower mold plate 14, and seats and unseats in the gate 20 to theinjection mold cavity 19. The actuator 66 is disposed in a chamber 40 ofthe upper mounting plate 39, with a radial clearance 3 provided in atleast one radial direction so as to facilitate the radial coupling anddecoupling of the pin head adapter 94 and actuator coupling 80.Similarly, there is a radial clearance 3 b/3 c to allow the projectingneck 75 and adapter 80 to move radially in the plates.

As described in U.S. Pat. No. 6,294,122 (the disclosure of which isincorporated herein by reference in its entirety as if fully set forthherein) the electric motor is powered and driven by electrical energy orpower input to coils that typically rotatably drive a magnet that inturn rotatably drives motor shaft 61.

In the FIGS. 1, 2 embodiment, the distal end of the rotor 61 of themotor 64 has a beveled gear head 191 that meshes with and rotatablydrives a beveled gear head 190 formed on the shaft of a lineartravelling XX screw 72 (linear travel converter) that comprise thetransmission assembly 58 a. As shown, the gear head 190 is integrallyformed together with a shaft having a downstream end that has malethreads forming a screw 72 that is screwably engaged within the femalescrews bored within the upstream head 195 of a linear conversion screw197. The downstream distal end of the screw 197 is connected to actuatorcoupling 80 which removably receives the upstream head portion 94 ofvalve pin 31 as described in detail in U.S. Pat. No. 8,091,202. Thedriven rotation motion 61R of motor shaft 61 is thus converted fromrotatable motion to controllably driven linear motion XX along axis X ofthe valve pin 31 via the driven rotation of the gear screw 72 and drivenlinear movement of the linear conversion screw 197 via the screwableengagement of screw and head 195.

As shown in FIGS. 1, 2 the arrangement or disposition of the motor axisY is non-coaxial to the axis X of the transmission gear and screws 72,195, 197 and valve pin 31. As shown the arrangement of the axes X and Ycan be about 90 degrees relative to each other. Alternatively, the axisY1 of the drive shaft can be disposed at any non-coaxial angle betweenzero and 180 degrees relative to the axis X of the transmission andvalve pin, the design of the meshed gears 190, 191 being adapted toenable such an arrangement.

FIGS. 3A, 3B shows another gearing arrangement where a circular gear 800attached to distal end of motor drive shaft 61 is controllably rotatablydrivable 61R around axis Y to drive XX the gear rack 802 (linear travelconverter) along axis X via meshing of the gears of gear 800 with thegears of rack 802, the rack 802 being fixedly attached to the upstreamend of a linear traveler rod 197 a that is interconnected at itsdownstream end to coupler 80. Thus the valve pin when coupled to coupler80 is controllably drivable along the X axis by controlled driving ofthe shaft 61 of the motor around the perpendicular axis Y.

In another alternative embodiment shown in FIGS. 4, 5, 6 the motor 64housing (or the gear box housing 58) could be mounted to the topclamping plate or mounting plate in an arrangement such that the driveshaft 61 of the motor 64 is aligned along the Z axis and a gear attachedto the distal end of the shaft is meshed with a complementary gear atthe upstream end of a complementary linear travel converter screw or rodsimilar to those described above regarding the FIGS. 1-3B embodiments todrive the valve pin along the non-coaxial axis X.

In the FIGS. 5-9 embodiments, driven rotation movement 61R of a motorshaft 61 is similarly converted to linear movement XX viainterconnection of the motor shaft 61 to a pulley 61P andinterconnection of the transmission shaft to a transmission pulley 58Pwith the two pulleys 58P, 61P being rotatably interconnected by belt500. In such an embodiment, the axis Y of the motor rotor 61 isnon-coaxial to the axis X of the transmission, the axes X and Y shown asbeing disposed at 180 degrees to each other. Other non-coaxially alignedarrangements of the axes X and Y, other than 180 degrees, can beassembled using appropriate components to interconnect pulleys 58P, 61P.

FIG. 9 shows an embodiment where the transmission pulley 58P has acentral internal thread that screwably receives a complementary threadedscrew shaft 58S that is driven axially XX by rotation of the pulley 58P.The downstream end of the screw shaft 58S is interconnected to adownstream linear drive stem 195 a which is interconnected to orotherwise forms the valve pin 31 of the system. The drive stem 195 a isdriven linearly XX along X by screw shaft 58S. The drive stem 195 a isadapted to be non-rotatable by formation of a flat surface 195 f on theouter circumference of the stem 195 a and by mounting a stationarilymounted stop member 195S having a complementary flat surface 195 ff thatis engaged against the flat surface 195 f of the stem 195 a to preventrotation thereof. The stem 195 a can be a separate part or can be formedas integral with the valve pin itself, in either case the valve pinbeing non-rotatably by virtue of the flats 195 f, 195 ff.

An electronic controller 176 can be interconnected to the electricmotor. Such a controller is capable of precisely driving the electriccoils according to any pre-programmed electronic program, circuit ormicrocontroller to in turn precisely drive the valve pin to any selectedpositions along the axis X such that the position of the tip end of thevalve pin relative to the gate is precisely controlled over the courseof an injection molding cycle.

A position sensor 178 can be used to sense the position of any componentof the system that relates to the axial X of the valve pin 31. Such asensor 178 can sense 177 the rotational or axial position of thetransmission gear 190, 72, the transmission linear conversion screw 195,the axis of the rotor 61 of the motor 64 such, the internal screw withinthe motor that drives the rotor or the magnet that drives the rotor 61,or the position sensor can alternatively sense 179 the axial position ofthe valve pin 31 itself. The signal 177, 179 that indicates position isinput to the controller 176 which can use such a real-time signal in aprogram to control the rate of drive of the motor rotor 61 andtransmission components 190, 72, 195 which in turn control the velocityor rate of travel of upstream withdrawal or downstream closure of thevalve pin 31 at selected times or over selected lengths of time over thecourse of an injection cycle.

With reference to FIGS. 10A-10M, the actuator assembly 66 is genericallydepicted as a box 66 for purposes of explanation as to how an assembly66 as described above can be coupled, decoupled and moved laterally andupstream-downstream within a complementary receiving recess providedwithin plates 39, 45 such that the pin coupling can be coupled to anddecoupled from the pin connector without having to dissemble the plates39, 45 or the actuator 66. Although FIGS. 10A-10M depict the actuator 66as a single parallelepiped shaped box, the box 66 as shown in FIGS.10A-10M is analogous to the differently shaped assemblies 66 asdescribed with reference to FIGS. 1-9 at least regarding how theassembly can be coupled, decoupled and moved within the recess 40 formedwithin plates 39, 45.

As shown in FIGS. 10A-10M the nozzle 18 is mounted in or on one or moremetal (e.g. stainless steel) plates. The apparatus includes a heatedmanifold 24 and one or more other spacer, mounting or mold plates 13,14. The manifold 24 is heated to maintain the nozzle 18 at an elevatedtemperature for delivery of the molten plastic. The mold cavity 19 andplates 13, 14 are typically maintained relatively cool by water coolingchannels compared to the manifold 24 to enable solidification of theinjected molten plastic to form a solid plastic article within thecavity of the mold.

The nozzle 18 is an elongated tubular article 19 typically made ofstainless steel and having a central axial bore 21 through which themolten plastic travels to the gate 20 and into the mold cavity. Also inthe nozzle bore, aligned along the central bore axis, is an axiallyelongated valve pin 30 having an axially elongated stem 31, whichdefines the valve pin axis AA. At one end of the stem, designed to seatand unseat in the nozzle gate for purposes of opening and closing thegate, and effectively starting and stopping flow of the molten plasticto the mold cavity, the stem has an angular or tapered lowermost tip 32.At the opposite or upstream (top) end 33 of the valve stem 31 is a pinhead 34 which in the present embodiment comprises a radially enlargedcylindrical member that is receivable within a pin head adapter 94. Thevalve stem 31 also extends through an elongated plastic feed bore 27 inthe heated manifold 24, typically also substantially coaxial with thenozzle bore. The valve stem 31 is guided into and mounted to themanifold 24 by a bushing 28 which receives, guides and mounts the valvestem 31 in the manifold plastic feed bore 27. The pin head 34 and anyassociated adapter 94 extends axially upstream beyond and from thebushing on the upstream or top side 25 of the manifold.

The pin head 34 may be formed integral with the valve stem 33 (as asingle part) or it may be formed as a separate part and then secured tothe upstream or top end of the valve stem by conventional means. It mayor may not be radially enlarged but is typically formed in a radiallyenlarged configuration for ease of ready connectivity to anddisconnectivity from an adapter component or pin coupling as describedbelow.

Above/upstream of the manifold 24, a pair of upper and lower mountingplates 39, 45 are provided in or on which the actuator 66 is mounted.The plates 39 and 45 are sometimes referred to as top clamping plates,clamping plates or backing plates. The actuator 66 via the transmissiondrives the valve pin stem axially A, X (linearly) along the coaxialbores of the manifold and nozzle. The housing of the actuator assembly66 is disposed within a receiving aperture or chamber 40 in the uppermounting plate 39 and/or a chamber 40 a in the lower mounting plate 45.As discussed above the assembly 66 can be fixed to the lower mountingplate 45 by threaded bolts 77 which extend into complementary threadedholes 50 in plate 45 so as to removably couple the actuator housing tothe mounting plate 39 (see FIG. 10F). In alternative embodiments asdiscussed above the actuator housing can be attached via bolts 79.

The mounting plates 39, 45 are removably coupled to the mold typicallyby bolts or similar reversible fastening mechanisms. The chamber 40 ofthe upper mounting plate 39 (in which the actuator 66 is disposed) isactually a through bore in the upper plate 39 extending from the topsurface 42 to the bottom surface 43. The neck 75 extends downwardly intoa co-axial bore 40 a/40 b in the lower mounting plate 45 (40/40 a/40 bare coaxial).

A pin coupling 80 is attached to or mounted on the neck 75 and is alsodisposed in the bore 40 a/40 b of the lower mounting plate 39 when theactuator is connected to the mounting plate. The coupling 80 includes aradial recess 83, disposed laterally (traverse to the elongated valvepin axis. The recess has a radial recess opening 82 that allows a pinhead 34 or pin head adapter 94 to be radially inserted into and removedfrom the radial recess. The coupling 80 also includes a radial slot 84,connected (open) to the radial recess and extending downwardly to thelower surface 90 of the coupling 80. The radial slot has a radial slotopening 85 through which the valve stem 31 can be readily radiallyinserted or translated within (or removed from) the slot 84 while theadapter 94 is simultaneously radially inserted or translated within (orremoved from) the radial recess 82. The coupling 80 has walls 91 thatform and act as a housing for the radial recess 83 and radial slot 84.As shown, the pin connector 94 and the recess 83 and recess opening 84are configured to have a complementary geometry, size, shape andconfiguration so as to enable the pin connector to be received withinthe recess 83 and fully surrounded and contained within walls 91 andalso to require that the pin connector 94 is receivable within andremovable from the recess 83 only by movement of the pin connector 94 ina radial direction R, FIG. 10B, transverse to the axial path of travel Aof the neck 75. The pin connector 94 is slidable by manual force alongradial direction R into and out of the recess 83 and recess opening 84.As shown when the pin connector 94 is slid into and out of recess 83 andopening 84, the pin stem 31 is simultaneously slidable radially throughslot opening 85 into slot 84. The walls 91 act to retain and couple thepin connector 94 and associated pin stem 31 to the neck 75 when theconnector 94 is received within recess 83 and stem 31 in slot 84.

In addition, the radial recess 82 is sized and configured to provide aradial clearance 2 in all radial directions between the valve pinadapter 94 and the recess 82 when/while the adapter is received andcoupled within the recess 82 of the coupling 80. This radial clearance 2allows movement in any radial direction of the valve pin adapter whileit is mounted in the recess of the actuator coupling, so as toaccommodate differences in thermal expansion between various componentsof the injection molding apparatus such as between the manifold 24 andthe mounting plates 39, 45. As previously described, the valve stem 31is mounted to a manifold 24 when the system is assembled, the manifoldbeing heated during the course of startup to a higher temperature thanthe relatively cold mounting plates 39, 45 and cold actuator 66. Duringthe time when the manifold 24 is being heated to a higher temperaturethan the mounting plates and actuator, it is desirable to provide aradial clearance to allow the valve pin assembly (pin 30 and adapter94), which is mounted to the manifold by the bushing 28 and travelsradially therewith and is also being heated via the manifold, to moveradially together with the manifold with respect to the mounting plateand the axial path of travel of the actuator so as to prevent theapplication of undesirable side bending forces on the valve pinassembly. These side forces may bend or break the valve stem orotherwise interfere with proper alignment and operation of the valve pinassembly and actuator.

FIGS. 10A, 10B show one embodiment of the coupling apparatus in anassembled state (FIG. 10A) and a disassembled state (10B). In FIG. 10A,the upper end of the valve pin is shown extending upwardly from amanifold bushing 28 secured to the top 25 of the manifold. The pin head34 and attached adapter 94, at the top end of the valve pin, aredisposed completely within the coupling 80 in FIG. 10A. The adapter 94is radially received in the radial recess 82 of the coupling 80, whilethe valve stem 31 resides in the radial slot 84 of the coupling. Thereis a radial clearance 2 provided between the interior surface 91 a ofthe walls 91 defining the radial recess 82 and outside surface of theadapter 94, and between the walls 91 b defining the radial slot 84 andvalve stem 31, to allow for radial movement of the valve pin assembly(here the valve stem 31, pin head 34 and pin head adapter 94) withrespect to the axial drive path A of the actuator 66. The actuatorcoupling 80 is connected to the spline shaft or neck 75 that isinterconnected to the electric actuator motor, by a pin 88 which extendsthrough a bore 87 in the coupling and into a bore in the shaft. Thisprevents rotation of the coupling relative to the actuator shaft.

FIG. 10B shows the disassembled pin coupling 80 and pin head adapter 94.A cylindrical set screw 104 having outer threads is adapted for threadedengagement with the pin head adapter 94. This is further illustrated inFIG. 10C-10D. The pin head adapter 94 has a central axial through bore99 extending from the top surface 96 to the bottom surface 97 of theadapter. The bore receives the upper end of the valve stem and pin head34. The pin head 34 sits on a shoulder 100 in the central bore and issecured in the adapter 94 by screwing the set screw 104 into a threadedupper portion of the bore, creating a pressure engagement of the pinhead and adapter. In this embodiment, the adapter essentially functionsas an enlarged pin head. In another embodiment, the adapter may not berequired, as the pin head itself could be disposed in the radial recessof the actuator coupling.

FIG. 10E shows the actuator housing including four bores 76, one in eachcorner of the housing, for receiving bolts 77 that removably couple themotor or gear housing 58, 64 to the lower mounting plate 45. Fourcomplementary tapped holes 50 are provided in the upper surface 48 ofthe lower mounting plate 45 for receiving the bolts 77 and securing themotor housing to the plate. This prevents rotational and other movementof the housing of the motor with respect to the mounting plates andmanifold and the injection molding apparatus generally. Extendingdownwardly from the motor or gear housing 58, 64 is a cylindricalprojection 74 from which the neck 75 extends. Coupled to the downstreamend of the neck 75 is the actuator coupling 80 and extending axiallydownstream from the coupling 80 is the valve stem 31.

FIG. 10F is a cross section showing the injection molding stack. Aspreviously described, a heated manifold 24 is disposed between themounting plates 39/45 and mold plates 13/14. In use, the mounting platesand mold plates are fixedly secured together under high clamp pressure,so as to withstand high injection molding forces. A nozzle 18 extendsthrough a bore 15 in the lower mold plate 14, and seats and unseats inthe gate 20 to the injection mold cavity. The actuator 66 housing isdisposed in a chamber 40 of the upper mounting plate 39, with a radialclearance 3 provided in at least one radial direction so as tofacilitate the radial coupling and decoupling of the pin head adapterand actuator coupling. Similarly, there is a radial clearance 3 b/3 c toallow the neck 75 and adapter 80 to move radial in the plates. FIG. 10Gis a top plan view of the apparatus of FIG. 10F, but with the electricmotor removed. The chamber 40 has a rectilinear cross section. Below thechamber 40, the upper bore 40 a has an oval cross section, and the lowerbore 40 b also has an oval but smaller, cross section, providing aradial clearance along the long axis L of the oval, to facilitate theassembly and disassembly steps described below.

FIGS. 10H-10M illustrate a variety of steps for decoupling the actuatorfrom the mounting plate 39 and for decoupling the valve pin assembly 30,94 from the actuator coupling 80 and the mounting plate 39, 45,according to one embodiment. In FIG. 10H, the actuator is shown coupledto the valve pin assembly, with the actuator secured to the lowermounting plate and the valve pin assembly mounted in the actuatorcoupling. This illustrates the actuator and valve pin assembly asassembled during the injection molding cycle, wherein the axial drivepath of travel XX of the actuator is substantially axially aligned withthe valve stem axis, as the valve stem extends through the axis of theplastic feed bores of the manifold 27 and nozzle 18. The mounting plates39 45 are clamped to the mold 12 with the manifold 24 secured betweenthe mounting plates and mold.

In FIG. 10I the bolts 77 are decoupled from the complementary receivingapertures 50 in the clamp plate 39 thus decoupling the actuator 66housing from the clamp plate 45. As shown the housing of the actuator 66and associated neck 75 are disposed upon decoupling of the housingwithin the plate receiving apertures 40, 40 a, 40 b. In FIG. 10J, thefirst two steps of disassembly have been performed. The bolts have beenremoved and then the actuator 66 housing is moved laterally or radiallyin direction S so as to decouple pin connector 94 from coupling 80 bysliding the connector 94 radially 102, (FIG. 10J) out of the recess 82,83 of the coupling. Upon such decoupling of the connector 94, the pinstem 31 and associated parts such as the pin head 34 and adapter 94 andset screw 104 remain behind mounted to the manifold 24 while theactuator 66, is still disposed on the plate 45 and within the recesses40, 40 a, 40 b of the mounting plates 39, 45. In a further subsequentoperation, the actuator 66 can be removed entirely, FIGS. 10K, 10L, forreplacement or repair of the actuator, from the recesses 40, 40 a.During this operation the valve pin assembly again remains stationaryand behind mounted to the manifold and does not require removal of thepin 30.

With reference to FIG. 10M, alternatively to removal of only theactuator 66, the mounting plates 39 and/or 45 can also be removed aloneor together with the actuator 66 from the mold 12 once the actuator isdecoupled from the pin connector 94 without requiring removal of thevalve pin 30 (and pin connector 94) from the manifold or nozzle. Thuseither the clamp plates 39, 45 can be removed from the system once thepin is decoupled from the actuator coupling 80, or the actuator 66 canremoved from the system once the pin is decoupled from the actuatorcoupling 80, or both the plates and the actuator can be removed from thesystem once the pin is decoupled from the actuator coupling 80, all suchremovals being accomplished without removal of the pin 30 from themanifold or nozzle.

In another aspect of the invention there is provided an apparatus forcontrolling the rate of flow of fluid mold material from an injectionmolding machine to a mold cavity, the apparatus comprising:

a manifold receiving the injected fluid mold material, the manifoldhaving a delivery channel that delivers the injected fluid material to afirst gate leading to the mold cavity;

an actuator interconnected to a valve pin having a tip end drivablealong a drive path that extends between a first position where the tipend of the valve pin obstructs the first gate to prevent the injectionfluid material from flowing into the cavity, a second position upstreamof the first position wherein the tip end of the valve pin restrictsflow of the injection fluid through the first gate along at least aportion of the length of the drive path extending between the firstposition and the second position, and a third position upstream of thesecond position where the injection fluid material flows freely throughthe first gate without restriction from the tip end of the pin,

the actuator and the valve pin being translationally driven at acontrollable rate of travel by a valve system that is controllablyadjustable between a start position, one or more intermediate drive ratepositions and a high drive rate position, the actuator being drivenupstream at one or more intermediate rates of travel when the valvesystem is in the one or more intermediate drive rate positions and at ahigher rate of travel than the one or more intermediate rates of travelwhen the valve system is in the high drive rate position;

a position sensor and a controller,

the position sensor sensing the position of the valve pin and sending asignal indicative of the position of the pin to the controller;

the controller instructing the valve system to drive the actuator andthe valve pin continuously upstream from the start position to thesecond position to the third position;

the controller including instructions that instruct the valve system tomove from the start position to the one or more intermediate drive ratepositions and subsequently from the one or more intermediate drive ratepositions to the high drive rate position on receipt by the controllerof a signal from the position sensor that is indicative of the valve pinhaving reached the second position.

Preferably, the valve pin and the gate are configured or adapted tocooperate with each other to restrict and vary the rate of flow of fluidmaterial 1153, FIGS. 11A-11B, 12A-12B over the course of travel of thetip end of the valve pin through the restricted velocity path RP. Mosttypically as shown in FIGS. 11A, 11B the radial tip end surface 1155 ofthe end 1142 of pin 1041, 1042 is conical or tapered and the surface ofthe gate 1254 with which pin surface 1155 is intended to mate to closethe gate 34 is complementary in conical or taper configuration.Alternatively as shown in FIGS. 12A, 12B, the radial surface 1155 of thetip end 1142 of the pin 1041, 1042 can be cylindrical in configurationand the gate can have a complementary cylindrical surface 1254 withwhich the tip end surface 1155 mates to close the gate 34 when the pin1041 is in the downstream gate closed position. In any embodiment, theoutside radial surface 1155 of the tip end 1142 of the pin 1041 createsrestricted a restricted flow channel 1154 over the length of travel ofthe tip end 1142 through and along restricted flow path RP thatrestricts or reduces the volume or rate of flow of fluid material 1153relative to the rate of flow when the pin 1041, 1042 is at a full gateopen position, namely when the tip end 1142 of the pin 1041 hastravelled to or beyond the length of the restricted flow path RP (whichis, for example the 4 mm upstream travel position of FIGS. 13A-13C).

In one embodiment, as the tip end 1142 of the pin 1041 continues totravel upstream from the gate closed GC position (as shown for examplein FIGS. 11A, 12A) through the length of the RP path (namely the pathtravelled for the predetermined amount of time), the rate of materialfluid flow 1153 through restriction gap 1154 through the gate 34 intothe cavity 30 continues to increase from 0 at gate closed GC position toa maximum flow rate when the tip end 1142 of the pin reaches a positionFOP (full open position), FIGS. 13A-13D, where the pin is no longerrestricting flow of injection mold material through the gate. In such anembodiment, at the expiration of the predetermined amount of time whenthe pin tip 1142 reaches the FOP (full open) position FIGS. 13A, 13B,the pin 1041 is immediately driven at maximum velocity FOV (full openvelocity).

In alternative embodiments, when the predetermined time for driving thepin at reduced velocity has expired and the tip 1142 has reached the endof restricted flow path RP2, the tip 1142 may not necessarily be in aposition where the fluid flow 1153 is not still being restricted. Insuch alternative embodiments, the fluid flow 1153 can still berestricted to less than maximum flow when the pin has reached thechangeover position COP2 where the pin 1041 is driven at a higher,typically maximum, upstream velocity FOV. In the alternative examplesshown in the FIGS. 11B, 12B examples, when the pin has travelled thepredetermined path length at reduced velocity and the tip end 1142 hasreached the changeover point COP, the tip end 1142 of the pin 1041 (andits radial surface 1155) no longer restricts the rate of flow of fluidmaterial 1153 through the gap 1154 because the gap 1154 has increased toa size that no longer restricts fluid flow 1153 below the maximum flowrate of material 1153. Thus in one of the examples shown in FIG. 11B themaximum fluid flow rate for injection material 1153 is reached at theupstream position COP of the tip end 1142. In another example shown inFIG. 11B 12B, the pin 1041 can be driven at a reduced velocity over ashorter path RP2 that is less than the entire length of the restrictedmold material flow path RP and switched over at the end COP2 of theshorter restricted path RP2 to a higher or maximum velocity FOV. In theFIGS. 13A, 13B examples, the upstream FOP position is about 4 mm and 5mm respectively upstream from the gate closed position. Otheralternative upstream FOP positions are shown in FIGS. 13C, 13D.

In another alternative embodiment, shown in FIG. 12B, the pin 1041 canbe driven and instructed to be driven at reduced or less than maximumvelocity over a longer path length RP3 having an upstream portion URwhere the flow of injection fluid mold material is not restricted butflows at a maximum rate through the gate 34 for the given injection moldsystem. In this FIG. 12B example the velocity or drive rate of the pin1041 is not changed over until the tip end of the pin 1041 or actuator941 has reached the changeover position COP3. As in other embodiments, aposition sensor senses either that the valve pin 1041 or an associatedcomponent has travelled the path length RP3 or reached the end COP3 ofthe selected path length and the controller receives and processes suchinformation and instructs the drive system to drive the pin 1041 at ahigher, typically maximum velocity upstream. In another alternativeembodiment, the pin 1041 can be driven at reduced or less than maximumvelocity throughout the entirety of the travel path of the pin during aninjection cycle from the gate closed position GC up to the end-of-strokeEOS position, the controller 16 being programmed to instruct the drivesystem for the actuator to be driven at one or more reduced velocitiesfor the time or path length of an entire closed GC to fully open EOScycle.

In the FIGS. 13A-13D examples, FOV is 100 mm/sec. Typically, when thetime period for driving the pin 1041 at reduced velocity has expired andthe pin tip 1142 has reached the position COP, COP2, the pins 1041, 1042are driven at the maximum velocity or rate of travel that the system iscapable of driving the actuators 941, 942. Alternatively, the pins 1041,1042 can be driven at a preselected FOV velocity that is less than themaximum velocity at which the pin is capable of being driven but isstill greater than the selected reduced velocities that the pin isdriven over the course of the RP, RP2 path to the COP, COP2 position.

At the expiration of the predetermined reduced velocity drive time, thepins 1041, 1042 are typically driven further upstream past the COP, COP2position to a maximum end-of-stroke EOS position. The upstream COP, COP2position is downstream of the maximum upstream end-of-stroke EOS openposition of the tip end 1142 of the pin. The length of the path RP orRP2 is typically between about 2 and about 8 mm, more typically betweenabout 2 and about 6 mm and most typically between about 2 and about 4mm. In practice the maximum upstream (end of stroke) open position EOSof the pin 1041, 1042 ranges from about 8 mm to about 18 inches upstreamfrom the closed gate position GC.

What is claimed is:
 1. An apparatus for controlling the rate of flow offluid mold material from an injection molding machine to a mold cavity,the apparatus comprising: a manifold that receives an injection fluidmold material, the manifold having a delivery channel that delivers theinjection fluid mold material under an injection pressure to a gate of amold cavity disposed within a mold, the gate being controllably openedand closed by a valve pin having a pin axis, the valve pin beingslidably mounted for reciprocal upstream and downstream linear movementalong the pin axis such that a downstream end of the valve pin isdrivable into and out of open and closed positions relative to the gate,an electric actuator comprising an electric motor comprised of a motorhousing that houses a drive shaft having a drive gear and a drive axisthat is rotatably mounted within the motor housing and is drivablyrotatable around the drive axis by a source of electrical power orenergy and a transmission comprised of a transmission gear rotatablymounted within a transmission housing, the transmission gear having agear axis and being drivably rotatable around the gear axis, the drivegear, the transmission gear and the valve pin being drivablyinterconnected and arranged such that the drive axis and the gear axisare non-coaxially mounted or disposed relative to each other and suchthat driven rotation of the drive gear around the drive axis rotatablydrives the transmission gear around the gear axis and linearly drivesthe valve pin along the pin axis, a controller that controllablyoperates the motor to control the velocity or rate of travel of upstreamwithdrawal or downstream closure of the valve pin with respect to thegate at selected, valve pin positions, selected times or over selectedlengths of time over the course of an injection cycle, and a positionsensor that senses a position of either the actuator or the valve pin,and sends a signal indicative of the position of the actuator or thevalve pin to the controller; wherein the controller includesinstructions that instruct the actuator to drive the valve pin upstreamfrom a gate closed position to an intermediate upstream position at areduced velocity, the controller further including instructions thatinstruct the actuator to drive the valve pin upstream from theintermediate upstream position at a velocity that is higher than thereduced velocity on detection by the position sensor of the valve pin atthe intermediate upstream position.
 2. The apparatus of claim 1 whereinone or the other of the motor housing or the transmission housing areremovably attached to a top clamping or mounting plate.
 3. The apparatusof claim 1 wherein the valve pin is driven at the reduced velocity overa path length of between about 2 and about 4 mm.
 4. The apparatus ofclaim 3 wherein the controller includes instructions that instruct theactuator to drive the valve pin upstream from a gate closed position tothe intermediate upstream position at a velocity that is less than amaximum velocity at which the actuator is capable of driving the valvepin.
 5. The apparatus of claim 1 wherein the controller includesinstructions that instruct the actuator to drive the valve pin upstreambeginning from the closed position to one or more intermediate upstreampositions at one or more intermediate rates of travel that are less thana maximum velocity at which the actuator is capable of driving the valvepin for either a predetermined amount of time or for a predeterminedlength of upstream travel.
 6. The apparatus of claim 1 wherein thecontroller includes instructions that instruct the actuator to drive thevalve pin upstream from the one or more intermediate upstream positionsto an upstream end of stroke position at one or more high rates oftravel that are greater than the one or more intermediate rates oftravel.
 7. The apparatus of claim 1 wherein the controller includesinstructions that instruct the actuator to drive the valve pin at one ormore high rates of downstream travel that are equal to or less than amaximum rate of downstream travel at which the actuator is capable ofdriving the valve pin when the valve pin is disposed at an upstream endof stroke position during the course of an injection cycle.
 8. Theapparatus of claim 1 wherein the actuator is interconnected to acontroller that includes instructions that instruct the actuator todrive the valve pin upstream continuously beginning from the closedposition to one or more intermediate upstream positions at one or moreintermediate rates of travel that are less than a maximum velocity atwhich the actuator is capable of driving the valve pin for either apredetermined amount of time or for a predetermined length of upstreamtravel.
 9. The apparatus of claim 8 wherein the actuator includesinstructions that instruct the actuator to drive the valve pincontinuously upstream from the one or more intermediate upstreampositions to an upstream end of stroke position at one or more highrates of travel that are greater than the one or more intermediate ratesof travel.
 10. The apparatus of claim 1 wherein the controller includesinstructions that instruct the actuator to drive the valve pin at one ormore intermediate rates of downstream travel that are less than one ormore high rates of downstream travel on expiration of a predeterminedamount of time or for a predetermined amount of downstream travel of thevalve pin from an upstream end of stroke position.
 11. The apparatus ofclaim 1 wherein the controller includes instructions that instruct theactuator to drive the valve pin at one or more high rates of downstreamtravel that are equal to or less than a maximum rate of downstreamtravel at which the actuator is capable of driving the valve pin whenthe valve pin is disposed at an upstream end of stroke position duringthe course of an injection cycle, the controller including instructionsthat instruct the actuator to drive the valve pin at one or moreintermediate rates of downstream travel that are less than the one ormore high rates of downstream travel on expiration of a predeterminedamount of time or for a predetermined amount of downstream travel of thevalve pin between the upstream end of stroke position and the gateclosed position.
 12. The apparatus of claim 11 wherein the controllerinstructs the actuator to drive the valve pin continuously downstream atthe one or more intermediate rates of downstream travel on detection bythe position sensor of the valve pin having traveled the predeterminedamount of downstream travel between the upstream end of stroke positionand the gate closed position.
 13. A method of driving a valve pin inapparatus for controlling the rate of flow of fluid mold material froman injection molding machine to a mold cavity, the method comprisingoperating the apparatus of claim 1 to drive the valve pin along the pinaxis.
 14. A method of driving a valve pin in apparatus for controllingthe rate of flow of fluid mold material from an injection moldingmachine to a mold cavity, the apparatus comprising: a manifold thatreceives an injection fluid mold material, the manifold having adelivery channel that delivers the injection fluid mold material underan injection pressure to a gate of a mold cavity disposed within a mold,the gate being controllably opened and closed by a valve pin having apin axis, a pin stem and a pin connector, the valve pin being slidablymounted for reciprocal upstream and downstream linear movement along thepin axis such that a downstream end of the valve pin is drivable intoand out of open and closed positions relative to the gate, an electricactuator comprising an electric motor comprised of a motor housing thathouses a drive shaft having a drive gear and a drive axis that isrotatably mounted within the motor housing and is drivably rotatablearound the drive axis by a source of electrical power or energy and atransmission comprised of a transmission gear rotatably mounted within atransmission housing, the transmission gear having a gear axis and beingdrivably rotatable around the gear axis, the drive gear and thetransmission gear being drivably interconnected and arranged such thatthe drive axis and the gear axis are non-coaxially mounted or disposedrelative to each other and such that driven rotation of the drive geararound the drive axis rotatably drives the transmission gear around thegear axis, a controller that controllably operates the motor to controlthe velocity or rate of travel of upstream withdrawal or downstreamclosure of the valve pin at selected positions, selected times or overselected lengths of time over the course of an injection cycle, aposition sensor that senses a position of either the actuator or thevalve pin, and sends a signal indicative of the position of the actuatoror the valve pin to the controller; the method comprising: instructingthe actuator to drive the valve pin upstream from a gate closed positionto an intermediate upstream position at a reduced velocity, instructingthe actuator to drive the valve pin upstream from the intermediateupstream position at a velocity that is higher than the reduced velocityon detection by the position sensor of the valve pin at the intermediateupstream position.
 15. The method of claim 14 further comprisingmounting the actuator such that one or the other of the motor housing orthe transmission housing are removably attached to a top clamping ormounting plate.
 16. The method of claim 14 wherein the controllerinstructs the actuator to drive the valve pin upstream from a gateclosed position to an upstream position at a velocity that is less thana maximum velocity at which the actuator is capable of driving the valvepin.
 17. The method of claim 14 wherein the controller instructs theactuator to drive the valve pin at the reduced velocity over a pathlength of between about 2 and about 4 mm.
 18. The method of claim 14wherein the controller instructs the actuator to drive the valve pinupstream beginning from the closed position to one or more intermediateupstream positions at one or more intermediate rates of travel that areless than a maximum velocity at which the actuator is capable of drivingthe valve pin for either a predetermined amount of time or for apredetermined length of upstream travel.
 19. The method of claim 14wherein the controller instructs the actuator to drive the valve pinupstream from the one or more intermediate upstream positions to anupstream end of stroke position at one or more high rates of travel thatare greater than the reduced velocity.
 20. The method of claim 13wherein the controller instructs the actuator to drive the valve pin atone or more high rates of downstream travel that are equal to or lessthan a maximum rate of downstream travel at which the actuator iscapable of driving the valve pin when the valve pin is disposed at anupstream end of stroke position during the course of an injection cycle.21. The method of claim 14 wherein the controller instructs the actuatorto drive the valve pin upstream continuously beginning from the closedposition to one or more intermediate upstream positions at one or moreintermediate rates of travel that are less than a maximum velocity atwhich the actuator is capable of driving the valve pin for either apredetermined amount of time or for a predetermined length of upstreamtravel.
 22. The method of claim 14 wherein the controller instructs theactuator to drive the valve pin continuously upstream from the one ormore intermediate upstream positions to an upstream end of strokeposition at one or more high rates of travel that are greater than thereduced velocity.
 23. The method of claim 14 wherein the controllerinstructs the actuator to drive the valve pin at one or moreintermediate rates of downstream travel that are less than one or morehigh rates of downstream travel on expiration of a predetermined amountof time or for a predetermined amount of downstream travel of the valvepin between an upstream end of stroke position and the gate closedposition.
 24. The method of claim 14 wherein the controller instructsthe actuator to drive the valve pin at one or more high rates ofdownstream travel that are equal to or less than a maximum rate ofdownstream travel at which the actuator is capable of driving the valvepin when the valve pin is disposed at an upstream end of stroke positionduring the course of an injection cycle, the controller instructs theactuator to drive the valve pin at one or more intermediate rates ofdownstream travel that are less than the one or more high rates ofdownstream travel on expiration of a predetermined amount of time or fora predetermined amount of downstream travel of the valve pin between theupstream end of stroke position and the gate closed position.
 25. Themethod of claim 14 wherein the controller instructs the actuator todrive the valve pin continuously downstream at one or more intermediaterates of downstream travel on detection by the position sensor of thevalve pin having traveled a predetermined amount of downstream travelbetween an upstream end of stroke position and the gate closed position.26. An apparatus for controlling the rate of flow of fluid mold materialfrom an injection molding machine to a mold cavity, the apparatuscomprising: a manifold that receives an injection fluid mold material,the manifold having a delivery channel that delivers the injection fluidmold material under an injection pressure to a gate of a mold cavitydisposed within a mold, the gate being controllably opened and closed bya valve pin having a pin axis, the valve pin being slidably mounted forreciprocal upstream and downstream linear movement along the pin axissuch that a downstream end of the valve pin is drivable into and out ofopen and closed positions relative to the gate, an electric actuatorcomprising an electric motor comprised of a motor housing that houses adrive shaft having a drive gear and a drive axis that is rotatablymounted within the motor housing and is drivably rotatable around thedrive axis by a source of electrical power or energy and a transmissioncomprised of a transmission gear rotatably mounted within a transmissionhousing, the transmission gear having a gear axis and being drivablyrotatable around the gear axis, the drive gear, the transmission gearand the valve pin being drivably interconnected and arranged such thatthe drive axis and the gear axis are non-coaxially mounted or disposedrelative to each other and such that driven rotation of the drive geararound the drive axis rotatably drives the transmission gear around thegear axis and linearly drives the valve pin along the pin axis, whereinone or the other of the motor housing and the transmission housing areremovably attached to a top clamping or mounting plate, a positionsensor that senses a position of either the actuator or the valve pin,and sends a signal indicative of the position of the actuator or thevalve pin to a controller; the controller including instructions thatinstruct the actuator to drive the valve pin upstream from a gate closedposition to an intermediate upstream position at a reduced velocity, thecontroller further including instructions that instruct the actuator todrive the valve pin upstream from the intermediate upstream position ata velocity that is higher than the reduced velocity on detection by theposition sensor of the valve pin at the intermediate upstream position.27. The apparatus of claim 26 wherein the controller includesinstructions that instruct the actuator to drive the valve pin at thereduced velocity over a path length of between about 2 and about 4 mm.28. A method of performing an injection molding process comprisingoperating an apparatus according to claim 26.